scummvm/engines/scumm/proc3ARM.s
Willem Jan Palenstijn a6ba9f150a SCUMM/ARM: Fix crashes in ARM asm costume renderer
It was possible to bypass the initialization of r11, and
mask was being read before the corresponding bounds check.

Thanks to fuzzie for analysis and LordHoto for testing.

This fixes bug #3500023 and a crash in the DOTT ending.
2012-04-04 08:54:58 +02:00

310 lines
7.2 KiB
ArmAsm

@ ScummVM - Graphic Adventure Engine
@
@ ScummVM is the legal property of its developers, whose names
@ are too numerous to list here. Please refer to the COPYRIGHT
@ file distributed with this source distribution.
@
@ This program is free software@ you can redistribute it and/or
@ modify it under the terms of the GNU General Public License
@ as published by the Free Software Foundation@ either version 2
@ of the License, or (at your option) any later version.
@
@ This program is distributed in the hope that it will be useful,
@ but WITHOUT ANY WARRANTY; without even the implied warranty of
@ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
@ GNU General Public License for more details.
@
@ You should have received a copy of the GNU General Public License
@ along with this program@ if not, write to the Free Software
@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
@
@ @author Robin Watts (robin@wss.co.uk)
.text
.global _ClassicProc3RendererShadowARM
.set _scaleIndexY , 112
.set _numStrips , 108
.set _palette , 104
.set _shadow_table , 100
.set _scaleIndexX , 96
.set _scaleX , 92
.set _height , 88
.set store_r14 , 84
.set store_r11 , 80
.set store_r10 , 76
.set store_r9 , 72
.set store_r8 , 68
.set store_r7 , 64
.set store_r6 , 60
.set store_r5 , 56
.set store_r4 , 52
.set src , 48
.set height , 44
.set len , 40
.set v1_shr , 36
.set v1_skip_width , 32
.set v1_destptr , 28
.set v1_scaleXstep , 24
.set v1_mask_ptr , 20
.set v1_y , 16
.set v1_scaletable , 12
.set pitch , 8
.set scaleIdxXPtr , 4
.set scaleIdxYPtr , 0
.set space , 48
@ r0 = _scaleY
@ r1 = v1
@ r2 = _out
@ r3 = src
@ <> = _height
@ <> = _scaleX
@ <> = _scaleIndexX
@ <> = _shadow_table
@ <> = _palette
@ <> = _numstrips
@ <> = _scaleIndexY
_ClassicProc3RendererShadowARM:
@ shadow20 = false
@ shadowed = true
@ unscaled = false
STMFD r13!,{r3-r11,r14}
LDRH r6,[r2,#2]
LDRH r7,[r2] @ r7 = _out.w
LDRH r8,[r2,#4] @ r8 = _out.pitch
ADD r6,r6,#1 @ r6 = _out.h+1
SUB r13,r13,#space
STR r3,[r13,#src]
STR r8,[r13,#pitch]
LDMIA r1,{r3,r4,r5,r8,r9,r10,r11}
@ r3 = v1.x
@ r4 = v1.y
@ r5 = scaletable
@ r8 = skip_width
@ r9 = destptr
@ r10= mask_ptr
@ r11= scaleXstep
LDR r2, [r13,#_scaleIndexY]
LDR r12,[r13,#_scaleIndexX]
STR r4, [r13,#v1_y]
STR r5, [r13,#v1_scaletable]
ADD r2, r5,r2 @ r2 = &scaletable[_scaleIndexY]
ADD r5, r5,r12 @ r5 = &scaletable[_scaleIndexX]
STR r5, [r13,#scaleIdxXPtr]
STR r2, [r13,#scaleIdxYPtr]
STR r8, [r13,#v1_skip_width]
LDRB r8, [r1,#29] @ r8 = shr
LDRB r14,[r1,#31] @ r14= replen
LDRB r1, [r1,#30] @ r1 = repcolor
STR r8, [r13,#v1_shr]
STR r9, [r13,#v1_destptr]
STR r10,[r13,#v1_mask_ptr]
STR r11,[r13,#v1_scaleXstep]
LDR r12,[r13,#_height]
@ r0 = _scaleY
@ r1 = v1.repcolor
@ r2 = &v1.scaletable[scaleIndexY]
@ r3 = v1.x
@ r4 = v1.y
@ r5 =
@ r6 = _out.h+1
@ r7 = _out.w
@ r8 =
@ r9 = v1.destptr
@ r10= v1.mask_ptr
@ r11=
@ r12= _height
@ r14= v1.replen
MOV r8,#0x80
AND r11,r3,#7 @ r11= v1.x & 7
MOV r8,r8,LSR r11 @ r8 = maskbit = revBitMask(v1.x & 7)
ADD r10,r10,r3,ASR #3 @ r10= mask = v1.mask_ptr + (v1.x>>3)
@ r0 = _scaleY
@ r1 = color = v1.repcolor
@ r2 = &v1.scaletable[scaleIndexY]
@ r3 = v1.x
@ r4 = y = v1.y
@ r5 =
@ r6 = _out.h+1
@ r7 = _out.w
@ r8 = maskbit
@ r9 = v1.destptr
@ r10= mask
@ r11=
@ r12= height = _height
@ r14= len = v1.replen
CMP r14,#0
BEQ outerloop
ADD r12,r12,#1 @ r12= height++
MOV r5,r12 @ r5 = loopCount = height
CMP r5,r14 @ if (loopCount > len)
MOVGT r5,r14 @ loopCount = len
SUB r12,r12,r5
SUB r14,r14,r5
STR r12,[r13,#height]
STR r14,[r13,#len]
LDR r12,[r13,#pitch]
LDR r11,[r13,#_numStrips]
B startpos
outerloop:
@ r0 = _scaleY
@ r1 = color
@ r2 = &v1.scaletable[scaleIndexY]
@ r3 = x
@ r4 = y
@ r5 =
@ r6 = _out.h+1
@ r7 = _out.w
@ r8 = maskbit
@ r9 = dst
@ r10= mask
@ r11=
@ r12= height
@ r14=
LDR r11,[r13,#src]
LDR r5,[r13,#v1_shr]
@ stall
LDRB r14,[r11],#1 @ r14= len = *src++
@ stall
@ stall
MOV r1, r14,LSR r5 @ r1 = color = len>>v1.shr
BICS r14,r14,r1,LSL r5 @ r14= len
LDREQB r14,[r11],#1 @ if (!len) r14 = len = *src++
STR r11,[r13,#src]
CMP r14,#0
middleloop:
@ r0 = _scaleY
@ r1 = color
@ r2 = &v1.scaletable[scaleIndexY]
@ r3 = x
@ r4 = y
@ r5 = loopCount = min(height,len)
@ r6 = _out.h+1
@ r7 = _out.w
@ r8 = maskbit
@ r9 = dst
@ r10= mask
@ r11=
@ r12= height
@ r14= len
MOV r5,r12 @ loopCount = height
CMPNE r5,r14 @ if (len != 0 && loopCount > len)
MOVGT r5,r14 @ loopCount = len
SUB r12,r12,r5 @ height -= loopCount
SUB r14,r14,r5 @ len -= loopCount
STR r12,[r13,#height]
STR r14,[r13,#len]
LDR r11,[r13,#_numStrips]
LDR r12,[r13,#pitch]
@ r0 = _scaleY
@ r1 = color
@ r2 = &v1.scaletable[scaleIndexY]
@ r3 = x
@ r4 = y
@ r5 = loopCount = min(height,len)
@ r6 = _out.h+1
@ r7 = _out.w
@ r8 = maskbit
@ r9 = dst
@ r10= mask
@ r11= _numStrips
@ r12= _out.pitch
@ r14= scratch
innerloop:
@ inner loop
CMP r0,#254 @ if _scaleY <= 254
LDRLEB r14,[r2],#1 @ r14 = v1.scaletable[scaleIndexY++]
@ stallLE
@ stallLE
CMPLE r0,r14 @ || _scaleY >= r14
BLE startpos
ADDS r4,r4,#1 @ y >= 0 (equiv to y>-1,y+1>0)
CMPGT r1,#0 @ && color > 0
CMPGT r6,r4 @ && _out.h+1 > y+1
CMNGT r3,#1 @ && x >= 0 (equiv to x>-1,x+1>0)
CMPGT r7,r3 @ && _out.w > x
BLE masked
LDRB r14,[r10] @ r14 = mask[0]
TST r14,r8 @ && !(mask[0] && maskbit)
LDREQ r14,[r13,#_palette]
BNE masked
@ stall
LDRB r14,[r14,r1,lsl#1] @ r14 = pcolor = _palette[color]
@ stall
@ stall
CMP r14,#13 @ if (pcolor == 13)
LDREQ r12,[r13,#_shadow_table]
LDREQB r14,[r9] @ r14 = *dst
@ stallEQ
@ stallEQ
LDREQB r14,[r12,r14] @ r14 = pcolor=_shadow_tab[r14]
LDREQ r12,[r13,#pitch]
@ stallEQ
STRB r14,[r9] @ *dst = pcolor
masked:
ADD r10,r10,r11 @ mask += _numStrips
ADD r9,r9,r12 @ dst += _out.pitch
startpos:
SUBS r5,r5,#1 @ loopCount -=1
BNE innerloop
@ So we either ran out of height or len (or both)
LDR r12,[r13,#height]
LDR r14,[r13,#len]
CMP r12,#0
BNE notheight
LDR r10,[r13,#v1_skip_width]
LDR r11,[r13,#_scaleX]
LDR r2,[r13,#scaleIdxXPtr]
LDR r12,[r13,#v1_scaleXstep]
SUBS r10,r10,#1 @ if --v1.skip_width == 0
BEQ end @ return _scaleIndexX
LDRB r9,[r2],r12 @ r2 = scaleIdxXPtr+=sclXstp
STR r10,[r13,#v1_skip_width]
CMP r11,#254 @ if _scaleX <= 254
CMPLE r11,r9 @ && _scaleX <= scltb[scIdxX]
LDR r9,[r13,#v1_destptr] @ r9 = dst = v1.destptr
BLE noXstep
SUB r11,r7,#1
ADDS r3,r3,r12 @ v1.x += v1.scaleXstep
@ if v1.x < 0 ||
CMPGE r11,r3 @ _out.w-1 < v1.x
BLT end
AND r11,r3,#7
MOV r8,#0x80
MOV r8,r8,LSR r11 @ maskbit = revBitMask(v1.x & 7)
ADD r9,r9,r12 @ r10 = v1.destptr += v1.scaleXstep
STR r9,[r13,#v1_destptr]
noXstep:
STR r2,[r13,#scaleIdxXPtr]
LDR r10,[r13,#v1_mask_ptr]
LDR r12,[r13,#_height] @ r12= height = _height
LDR r4,[r13,#v1_y] @ r4 = y = v1.y
LDR r2,[r13,#scaleIdxYPtr] @ r2 = v1.scaletable[sclIdxY]
ADD r10,r10,r3,ASR #3 @ mask=v1.mask_ptr+(v1.x>>3)
notheight:
CMP r14,#0 @ while (len > 0)
BGT middleloop
B outerloop @ while (1)
end:
LDR r0,[r13,#v1_scaletable]
SUB r0,r2,r0
ADD r13,r13,#space
LDMFD r13!,{r3-r11,PC}